Tube bending tool



April 30, 1968 R w so ET AL 3,380,283

TUBE BEND ING TOOL 3 Sheets-Sheet 1 Filed Jan. 11, 1965 INVENTORS 3FQfi/VK 1?. W/zso/v i JOHN H. s TH/VLEY Y ATTORNEY April 30, 1968 F. R.WILSON ET AL 3,380,283

TUBE BENDING TOOL Filed Jan. 11, 1965 3 Sheets-Sheet 2 INVENTORS FQfi/VKE Mason) 4 Jog/v 15 STHIVLEY ATTORNEY April 30, 1968 R WILSON ET AL3,380,283

TUBE BENDING TOOL 5 Sheets-Sheet 3 Filed Jan. 11, 1965 United StatesPatent M 3,380,283 TUBE BENDING TOOL Frank R. Wilson, Memphis, Tenn.,and John H. Stanley,

Euclid, Ohio, assignors to Parker-Hannifiu Corporation, Cleveland, Ohio,a corporation of Ohio Filed Jan. 11, 1965, Ser. No. 424,535 6 Claims.(Cl. 72-387) ABSTRACT OF THE DISCLOSURE A tube bending tool including ashoe, a circular arbor and an elongated link pivotally connected by pinsat opposite ends of the link to the shoe and arbor, respectively; thedistance between the pivot pins being greater than the sum of the radiusof the arbor seat and the distance between .the shoe pin and thelongitudinal axis of the shoe seat, and releasable means for locking theshoe and arbor in a closed position in which the arbor seat and shoeseat engage the tube.

This invention relates to a tube bending tool, and more particularly toa portable hand tool for bending a tube.

Heretofore, portable tube bending tools have included an arbor and ashoe pivotally connected to the arbor for rotation about the arbor tobend a tube. However, in order to open the tool to receive the tube, theshoe has to be pivoted relative to the arbor, so that the handle on theshoe is swung upwardly and away from the tube. This type of tooloperates satisfactorily where plenty of room for pivoting the shoe andshoe handle is available. However, such a tool could not be used wherethe available space is limited, since the tool could not be opened andclosed to receive and release the tube.

It is therefore an object of this invention to overcome the abovedisadvantages by providing a tube bending tool in which the shoe and thearbor may be moved away from each other for receiving the tube withoutrotating the shoe relative to the arbor.

Another object of this invention is .to provide a portable tube bendingtool which may be operated in limited spaces.

A further object of this invention is to provide a portable tube bendingtool including a shoe and an arbor, and a link pivotally connecting theshoe and the arbor in offset relationship so that the shoe and arbor maybe swung toward and away from each other between a closed and an openposition, without changing the angular relationship of the shoe and thearbor.

A further object of this invention is to provide a portable, manual,tube bending tool which may be operated with a minimum of head space.

Another object of this invention is to provide a portable tube bendingtool including means for locking the shoe relative to the link in closedtube bending position for establishing a predetermined fixed radialposition of the shoe relative to the arbor.

Another object is to provide a portable tube bending tool in which theshoe and arbor are each pivotally connected to a link that in oneposition of the link relative to the shoe and arbor separates the sameso as to permit insertion of a tube therebetween and in another positioncloses the shoe against the tube, and there being a means to releasablylock the pivotal position of the shoe relative to the link when the shoeis in such closed position.

Further objects and advantages of the invention will be apparent fromthe following description taken in conjunction with the drawings,wherein:

FIGURE 1 is a side elevation of the invention in open position;

3,386,283 Patented Apr. 30, 1968 FIGURE 2 is a front end elevation ofthe invention disclosed in FIGURE 1;

FIGURE 3 is an elevation of the opposite side of the invention in closedposition;

FIGURE 4 is a rear end elevation of the invention disclosed in FIGURE 3;

FIGURE 5 is a side elevation of an optional form of the invention inclosed position; and

FIGURE 6 is a rear elevation of the invention disclosed in FIGURE 5.

Referring now to the drawings in more detail, the tool 10 for bending anelongated tube or rod 11 includes a circular arbor 13 and a shoe I14.The arbor 13 is provided with an annular recess or seat 16 having across section adapted to conform in size and shape to the cross sectionof the tube 11, as disclosed in FIGURES 2 and 4. Fixed to one side ofthe arbor 13 is a housing 17 in which is dependingly mounted anelongated lower or arbor handle 18.

Pivotally mounted on the rear end or edge of the arbor 13 is a book 20secured by a pivot pin or bolt 21. The length and size of the hook 20are such that when it is swung to operative position, disclosed in thedrawings, it will engage the top of the tube 11 when the tube :11 isreceived in the arbor seat 16 in its initial or stationary position. Theportion of the tube 11 to the rear of the arbor 13 is held in thisstationary position by the hook 20 during the bending operation,disclosed in FIGURE 3.

The shoe 14 has a front end or face 24 and a rear end 25 having a lowercut-out portion 26 adapted to clear the hook 20 when the tool is in itsoperative closed position, as disclosed in FIGURE 3. The bottom of theshoe 14 comprises a straight elongated seat 27 having an arcuate crosssection adapted to oppose the arbor seat 16 and engage the top portionof the tube 11, as disclosed in FIGURES 3 and 4. Rigidly secured in theshoe r14 and extending forwardly from the front face 24 is the elongatedupper or shoe handle 28. The handle 28 extends generally forwardly, butdiverges slightly from the tube 11 in order to provide leverage andgripping room for manipulating the shoe handle 28.

Connecting the arbor 13 and the shoe 14 together is a link or link bar30 having a rear end or face 31, an inclined upper forward face 32 and alower inclined face 33. A lower pivot pin 35 pivotally connects thelower end of the link 30 to the arbor 13 so that the pivotal axis of thepin 35 coincides with the center of the circular arbor 13. An upperpivot pin 36 is fixed in the rear portion of the shoe 14 and extendsthrough an elongated slot 37 in link 30 in slidable and pivotalengagement therewith. For the purposes of this invention, thelongitudinal axis 40 of the link 30 will be considered as the line ofcenters extending through the pivotal axis of the lower pin 35 and thepivotal axis of the upper pin 36 when the pin 36 is seated in the upperportion of elongated slot 37, as disclosed in FIGURES 1 and 3.

Formed in the lower front face 33 of the link 30 is an open endedlocking slot 42 which is adapted to receive in closed position, asindicated in FIGURES 3 and 4, a locking pin 43 fixed in the lowerportion of the shoe 14. The axis of the elongated slot 37 is directedgenerally toward the slot 42 and the latter is of a sufiicient angle andlength to permit the pin 43 to be easily inserted and removed from slot42 when the shoe 14 is pivoted about the pin 36 between its openposition disclosed in FIG- URE 1 and its closed position disclosed inFIGURE 3.

The operation of the invention is disclosed in the drawings,particularly FIGURES 1 and 3. Assuming that the tool 10 includes acircular arbor 13 having the appropriate seat 16 for receiving acorrespondingly sized tube 11 for bending, the handle 18 is grasped byone hand of the operator, for example, his left hand and the upperhandle 28 is grapsed by the right hand and the shoe 14 is moved to theopen position disclosed in FIGURE 1. It will be noted that the upperpivot pin 36 is raised to the disclosed upper position in the slot 37 toprovide the maximum space between the seats 16 and 27. In this initialposition, the hook 20 will be hanging down from its pivot pin 21 in aninoperative position, not shown. The tube 11 is then insertedlongitudinally between the seats 16 and 27 so that it rests upon theupper portion of the arbor seat 16. Alternatively, the tube may beinserted laterally from the side opposite link 30 by rotating the tube afew degrees in a counterclockwise direction from the position shown inFIGURE 1, in which case the tube will readily pass sidewards between thelower corner of cut-out portion 26 and arbor 13 because the latter arethen spaced apart a distance slightly greater than the diameter of thetube. The hook 20 is then rotated upwardly and over the top of the tube11 to hold the tube 11 in its initial stationary position illustrated inFIGURES l and 2.

The tool is then closed by thrusting the handle 28 rearwardly causingthe link 30 to pivot about the pivot pins 35 and 33 and also to swingrearwardly to the closed position illustrated in FIGURE 3, with the shoeseat 27 engaging the top portion of the tube 11. In moving the shoe 14rearwardly, the pivot pin 36 moves toward the bottom end of slot 37 sothat the locking pin 43 will ride downwardly over the upper forward face32 of the link 30 and continue down the lower forward face 33 until thepin 43 is seated in the slot 42, as indicated in FIGURE 3. The rearwardmovement of the shoe 14 is continued until the pin 36 again is seated inthe upper portion of slot 37, as illustrated in FIGURE 3. With the shoe14 locked in the closed position of FIGURE 3, the operator pressesdownwardly on the upper handle 28 in a clockwise direction, as viewed inFIGURE 3, to cause the shoe 14 to bend a portion 11' of the tube 11between the seats 16 and 27 to any desired position, such as illustratedin FIG- URE 3.

In order to determine the degree of bending, radial gauge marks 45 maybe provided on the side face of the arbor 13 and an indicator mark 46may be formed on the same side face adjacent the bottom of the shoe 14as disclosed in FIGURE 3. Thus, as the shoe is rotated, the indicatormark 46 will designate the degree of bend when it registers with eachsuccessive gauge mark 45, depending upon the calibration of the marks45.

After the tube 11 has been bent to the desired angle, such as tubeportion 11, the movement of the handle 28, and consequently the shoe 14,is reversed until it reaches the initial closed position disclosed inFIGURE 3. The handle 28 is then pulled forwardly, initially moving theshoe 14 to disengage the locking pin 43 from slot 42, and then rotatingthe link 30 to its open position, disclosed in FIGURE 1. The hook 20 isthen counter-rotated to disengage the tube 11 and the bent tube isremoved.

It will be noted that as the handle 28 is rotated in its closed positionto bend tube 11, the thrust of the shoe 14 will be such as to cause theupper pivot pin 36 to remain in the upper portion of elongated slot 37and also to thrust the locking pin 43 against the closed side of theslot 42, so that the shoe 14 will remain in locked position during thebending operation.

It will be further noted by observing the closed position of FIGURE 3and the open position of FIGURE 1 that the handle 28 and the shoe 14maintain the same relative rotational or angular position with respectto the arbor 13 and the handle 18. The only head space required for theshoe 14 and the handle 28 will be equal to the difference in the spacingbetween the arbor seat 16 and the shoe seat 27 in closed and openpositions. Thus, because the length of the link 30 permits the pivotalaxis of the upper pin 36 to be offset longitudinally from the axis ofthe lower pivot pin 35, the tool may be opened and closed without thenecessity of swinging the shoe 14 and the shoe handle 28 upwardly aboutthe pivot pin 36, which would require substantial head room. Therefore,the bending tool 10 can be employed for bending tube 11 in limitedspaces, areas with limited room and areas not readily accessible formanipulation of the tool by hand.

In the modification of the invention shown in FIG- URES 5 and 6, link 50is substituted for link 30 of FIG- URE l and it has a circular opening51 instead of an elongated slot 37 for receiving the pivot pin 36. Also,pin 43 and slot 42 are omitted. Instead, a book 52 is pivotally mountedon a pin 53 which is secured to the forward end of shoe 14 and which hasan enlarged central portion 54 for spacing hook 52 from shoe 14. Housing17 has a pin 55 extending therefrom on the center of circular arbor 13and hook 52 has a slot 56 for engaging pin 55.

To operate thhis form of the invention, hook 52 is initially swungupwardly to the dotted position shown in FIGURE 5, at which time shoe 14may be moved forwardly for rotating link 50 to a position correspondingwith FIGURE 1 in which the longitudinal axis 40 is perpendicular to theaxis of tube 11 in the stationary position of the latter. With the partsin this position, tube 11 may be inserted laterally between the shoe andarbor and into the seat 16 of the latter. After hook 20 is swung overthe tube, the shoe 14 may then be moved rearwardly to the position shownin FIGURE 5 and hook S2 swung downwardly to engage pin 55 in slot 56.This locks shoe 14 in its angular relationship with link 50 and the shoemay now be operated for bending the tube.

After the bend is completed, hook 52 is again swung into the positionshown in the dotted line in FIGURE 5, shoe 14 is moved forwardly and thetube may then be removed from the bender.

This arrangement not only provides an optional method of locking theangular relationship between the shoe and link 50 during the bendingoperation but also ties the shoe and arbor together so that there is aconnection between the shoe and arbor on each side thereof, link 50providing the connection on the opposite side. This imparts considerablerigidity to the assembly and prevents any springing action that wouldtend to separate the shoe and arbor during the bending operation.

It will be apparent to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof, and therefore the invention is not limited by that which isshown in the drawings and described in the specification, but only asindicated in the appended claims.

What is claimed is:

d. A tool for bending a tube comprising:

(a) an arbor having a seat for receiving said tube, said seat beingcircular in the bending plane of said tube,

(b) means adjacent one end of said arbor for holding one portion of saidtube in a stationary position relative to said arbor,

(c) a shoe having a seat with a longitudinal seat axis in said bendingplane, said shoe seat opposing said arbor seat for engaging said tube,

(d) a link having a longitudinal link axis, an upper end and a lowerend,

(e) a first pin pivotally connecting said lower end on said link axis tosaid arbor at the center of said circular seat,

(f) a second pin pivotally connecting said upper end on said link axisto said shoe to permit relative pivotal movement between said link andsaid shoe,

(g) the distance between said first and second pins on said link axisbeing greater than the sum of the radius of said arbor seat and thedistance between said second pin and said seat axis,

(h) said shoe being movable between an open position in which said linkaxis is perpendicular to said seat axis, and a closed position in whichsaid link axis forms an acute angle with said seat axis and said shoeseat and arbor seat engage said tube,

(i) handle means for moving said shoe between said open and closedpositions, and for rotating said shoe in closed position around saidarbor in said bending plane,

(j) a first locking member on said shoe,

('k) a second locking member on said link adapted to operatively engagesaid first locking member when said shoe and link are in closedposition, and

(1) means for releasably maintaining said first and second lockingmembers operatively engaged,

2. The invention according to claim 1 in which said one end of saidarbor is said rear end, said link having a front edge, said secondlocking member comprising an open slot in said front edge, said firstlocking member comprising a locking pin projecting from said shoe forengagement with said open slot when said shoe is rotated to said closedposition, said releasably maintaining means comprising an elongated slotin said link for receiving said second pin to facilitate the engagementand disengagement of said locking pin with said open slot.

3. The invention according to claim 2 in which said elongated slotextends in a direction generally toward said open slot.

4. The invention according to claim 2 in which said elongated slotextends at an acute angle with said link axis.

5. The invention according to claim 2 in which said elongated slot hasone end remote from said arbor, and said second pin is in alignment withsaid link axis when said second pin is received in said remote end.

6. The invention according to claim 2 in which, when said shoe is insaid closed position engaging a tube, only a portion of said shoe seatprojects toward a said holding means from a line perpendicular to saidseat axis passing through the center of said circular seat, and theentire shoe seat is on the opposite side of said line from said holdingmeans when said link axis is perpendicular to said seat axis.

References Cited

